Transmission control means



Jan; 24, 1950 J, E. F LEY 2,495,515

TRANSMISSION CONTROL MEANS Filed Feb. 1, 1946 Patented Jan. 24, 1950 TRANSMISSION CONTROL MEANS J crald E. Foley, Detroit, Mich., assignor to Packard Motor Car Company, Detroit, Mich, a corporation of Michigan Application February 1, 1946, Serial No. 644,681

12 Claims. (01. 74-472) This invention relates to transmissions and more particularly to control means for semiautomatic motor vehicle transmissions.

In semi-automatic motor vehicle transmissions having a plurality of gear ratios, the ratio selec-- tion for the high speed drive is usually under control of a speed sensitive device. There are some vehicle operating conditions where the best mechanical advantage cannot be obtained with high speed gear ratio when established by the speed sensitive device, for example, when the vehicle speed causes shift into the high speed gear ratio while there is a high torque demand.

An object of this invention is to provide an automatic transmission of the character referred to in which a speed sensitive control for high speed gear ratio is overruled above the governed speed until the torque demand is below some predetermined value.

Another object of the invention is to use a multiple gear ratio transmission to the best mechanical advantage by preventing the normal automatic up-shift by a speed sensitive device until torque in an established gear ratio falls below a predetermined value.

Another object of the invention resides in the automatic control of a plural gear ratio motor vehicle transmission in:which fuel intake manifold pressure is utilized to restrain shift from one gear ratio to a higher speed gear ratio by electromagnetic means responsive to vehicle speed while torque demand is above a predetermined value.

Other objects of the invention will appear from the following description taken in connection with the drawings, which form a part of this speciflcation, and in which:

Fig. 1 is a side elevation of transmission incorporating the invention; and

Fig. 2 is a sectional view of the transmission with the control means-shown schematically.

Numeral I represents generally a conventional type of vehicle transmission powered by a conventional internal combustion engine II. The transmission is suitably supported beneath the vehicle floor l2 and a conventional instrument panel l3 overlies the forward end of the floor.

The transmission includes a fluid coupling l4 having an impeller I5, driven directly by the engine crankshaft l6, and runners I1 and I8 for driving plural gear ratio mechanism in the form of planetary gearing. Runner 'I'I has gear i9 fixed thereto and runner l8 has gear 20 fixed thereto, such gears meshing respectively with planet gears 2i and 22. A'driven shaft 23 extends coaxial with the runners and carries gear 24 meshing with planet gear 25. Planet gears 21, 22 and 25 are formed as a unit or are fixed together and are rotatably mounted in carrier 26. Gears 20, 22, 25 and 24 provide the intermediate speed gear ratio drive and gears I9, 2|, 25 and 24 provide the low speed gear ratio drive.

Retrograde rotation of the carrier must be stopped when the engine is operating to establish either the low or intermediate speed drive and the planetary gearing must be locked to rotate as a unit to establish direct or high speed drive. The primary runner I1 is effective to drive the low speed gear train when the coupling impeller is rotating at low engine speed and a conventional one-way clutch 21 is provided in the primary runner so that the secondary runner l8 can overrun the primary runner when the coupling speed is such that the secondary runner becomes the driver for the intermediate speed gear train. The gear ratioselector control system includes two selector devices.

The selector device for holding the carrier from retrograde rotation is shown as a brake band 28 encircling the carrier and anchored at one end to the transmission casing 50 by pin 29. The other end of the band has a flange 30 to which an actuator 3! is fixed.

The selector device for locking the planetary gearing to rotate as a unit is shown as a friction clutch having alternate plates 32 slidably splined to shaft 23 and the carrier. The plates are engaged by a pressure operated actuator 33.

Actuators 3| and 33 for the brake and clutch devices are under the control of a pressure fluid system consisting of an engine driven pump 34 having an intake 35 extending into oil in the crankcase, a main conduit 36, branch conduits 31 and 3B and a selector valve device 39 between the main conduit and the branch conduits. This valve device consists of a housing 40 projecting into the transmission casing I 0' and containing leads from the valve housing and communicates with chamber 46 in an end of the carrier in which actuator 33 is slidably mounted. When the valve device allows flow through conduit 38, fluid 7 sesame;

. in the housing 46 is arranged to exert pressure against valv to normally position it 'in a station where branch conduit 58 is open to main conduit 83, branch conduit 3? being opento vent 52. when the valve is in such position the brake device will be released and the clutch will be applied to the carrier so that the high .speed gear ratio willfbe made eflective. Solenoid ht ilts into the valve casing es and serves to actuate valve stem 5!, when energized, to shift valve it to the right connecting conduit 38 with conduit 31, as shown in Fig. 2, and opening conduit 38 to vent 90 whereby the clutch device will be released and the brake device applied to the carrier to establish the drive in low or intermediategear ratio as dictated by the fluid clutch.

The solenoid control circuit includes battery II connected with contact 54 by lines 55 and 55, master switch 51 and line 58. The master switch is controlled by electromagnetic means comprising two systems, having oppositely disposed electromagnets 58 and 80, adapted to be alternately energized by switch 65 connected with line 55 and wiil="shiit:-- actuator. fiifito chem operable by a speed sensitive device 62. Switch tl is arranged between contacts 63 and 64, contact 63 being connected by line 65 with electromagnet 60 and contact 66 being connected by line 88 with electromagnet 59. The speed sensitive device may be of the flyweight governor type driven from vehicle tail shaft 61 by gearing 83 and operating an actuator 89 connected with switch Bl. The arrangement is such that below a predetermined vehicle speed, 12 miles per hour for example, switch 8| will engage contact and above such vehicle speed such switch will be moved to engage contact 63. Master switch 5'2? will be shifted intoand out of engagement with contact 54 depending upon the governor selection of current flow to the electromagnets. When magnet 58 is energized the master switch will engage contact 54 completing the circuit to solenoid 50 which acts tov position valve ll in the station shown in Fig. 2 whereby the brake device is applied and the clutch device disengaged.

When magnet 60 is energized switch 51 will be moved away from contact 54 thereby breaking the circuit to solenoid 50. Spring 48 is now free to move valve II to the left whereupon fluid flow to the brake device is cut off and conduits 36 and 38 are connected so that pressure fluidwill eng e the clutch device.

There are some vehicle operating conditions when this shift into high speed gear ratio is not desired if the most advantageous driving conditions are to be obtained. When high torque is required above the governed-speed, geared drive instead of direct drive dictated by the speed sensitive device is most advantageous. It is proposed to achieve this result with the circuit and control described by restraining movement of the master switch out of solenoid energizing position by an auxiliary circuit controlled by engine operating conditions as reflected by pressure in the engine intake manifold. Lines 66 and are connected respectively with contacts 10 and H and contact 1| is fixed to a movable switch member 12 in the form of a flexible diaphragm. Conduit 13 connects the engin fuel intake manifold 41 with the interior of casing 14 on which the diaphragm is fixed and spring I! in the casing mcvapontact n with stationary contact n.

Thus, above a predeterminedpressure in the manifold the circuit to electromagnet 59 will be maintained by this auxiliary circuit even though switched has been shifted above the governed speed to energize electromasnet 8E1. fiince flux density decreases rapidly with distance from the electromagnet, the master switch will be retained in contact with the electromagnet it is attracted to until the same is deenergized, and thus electromagnet 8i?) may be energized without drawing switch Ell away from electromagnet 59 so long as it remains energized. Vacuum or manifold pressure may thus be utilized for controlling the auxiliary circuit for maintaining low speed gear ratio in the transmission even though the speed sensitive device conditions the electromagnetic con-- gage contact 82 when thepedal is moved beyond wide open throttle position. Switch 85 is operable by the vehicle driver at the instrument panel l3 and may be moved to engage contact 83. These switches are in parallel in this auxiliary control circuit and either one may be actuated to energize the solenoid and cause the control valve to be shifted to cause engagement of the brake device when the main control system is in high speed gear ratio relation.

After high speed drive has been effected through engagement of clutch t2, the switch!- cannot be shifted back to geared drive position while the vehicle is above the governed speed except through the closure of either of th switches 84 and 85.

It will be understood that various forms of the invention other than that described above may be used without departing from the spirit or scope of the invention.

What I claim is:

1. In a control systemi'or selecting gear ratios in a vehicle transmission powered by an internal combustion engine having a fuel intake manifold. control devices operative to establish different gear ratios in the transmission, a pressure fluid system for actuating said control devices, a valve in said system movable to two stations for selecting fluid actuation of the control devices, means normally positioning said valve in one station, an electric system for shifting the valve to the other station when energized, a switch'in said system, electromagnetic means for shifting the switch, a governor operable to control the electromagnetic means, and means responsive to pres sure in the intake manifold for restraining movement of the switch in response to the governor controlled electromagnetic means.

2. In a vehicle transmission having two gear ratios, control devices selectively operable for establishing each gear ratio, a pressure fluid system for actuating said devices, a selector valve in said system movable to two stations for selecting fluid flow ,to said devices, means urging said valve to onestation, electromagnetic controlled means operable to shift the valve to the other station, governor means operative above a uum below a predetermined value. v

3. In a multiple gear ratio transmission for vehicles, a gear ratio controlmeans comprising individual control devices for effecting drive through the several gear ratios, a pressure fluid system for actuating said controldevices, a valve in said system movable to different stations for selecting fluid actuation'of the control devices,

means urging said valve to one station, an electric system for shifting the valve to another station, an electromagnetic system controlling said electric system, control means for the electromagnetic system including governor responsive means, effective above a predetermined vehicle speed to render a portion of the electromagnetic system ineffective, and vacuum influenced means effective in a high pressure range to restore the effectiveness of the said portion of the electromagnetic-system.

4. In control means for selecting gear ratios in a vehicle transmission powered by an internal combustion engine, devices operable to establish. different gear ratios in the transmission, a pressure fluid system operative to selectively control said .devices, a'valve in said system normally in' high speed gear ratio efiectingposition, a solenoid'operative to shift the valve to a lower speed gear ratio effecting position when energized, an electric circuit connected with the solenoid ineluding a master switch, an electromagnetic system for'shifting said switch in response to a pre-v determined vehicle speed,1 and means restraining shifting of the master switch from circuit form ing position under certain engine operating conditions.

5. In a control means for selecting gear ratios in a vehicle transmission powered by an internal combustion engine, devices-operable to establish diflerent gear ratios in the transmission, a pressure fluid system operative to selectively control said devices, a valve in said system normally held, in high speed gear ratio effecting position, a solenoid operative to shift the valve to a lower speed gear ratio effecting position when energized, an

electric circuit connected with the solenoid including a master switch, an electromagnetic system for shifting the master switch including a selector switch, governor means for shifting said selector switch at a predetermined vehicle speed, and means restraining deenergizing' of the elec-f tromagnetic system when holding the master switch in circuit making position under certain engine operating conditions.

6. In control means for selecting gear-ratios in vehicle transmissions, devices operable to establish different gear ratios in the transmission,

a pressure fluid system operative to selectively control said devices, a valve in said system norin a lower speed gear ratio position when energized, an electric circuit connected with the solenoid including a shiftable master switch, dual electromagnetic systems for shifting the master switch, a selector switch for the electromagnetic systems, andgovernor means operable above a predetermined vehicle speed for actuating said system for moving the master switch out of circuit makingposition.

.7. In control means for selecting gear ratios in vehicle transmissions, devices operable to establish different gear ratios in the transmission, a fluid pressure system operative'to selectively control said devices, a flow control valve in the system, spring means normally' maintaining the valve in. position to make the device for estab= lishing high speed gear ratio eiiective, a solenoid for shifting the valve to a position making the device for establishing a lower speed gear ratio effective when energized, an electric circuit connected with the solenoid, a master switch in said circuit, two electromagnetic means selectively operable to control shifting of said switch, and a switch selectively controlling energizing of said two electromagnetic means; and means responsive to a predetermined vehicle speed for shifting said switch controlling the electromagnetic means.

8; In a vehicle transmission of the planetary type having brake and clutch devices for establishing two gear ratios, control means for the devices comprising a fluid pressure systemoperthe solenoid including a make and break switch,

electromagnetic means controlled to hold the switch in circuit making position below a predetermined vehicle speed-and to shift the switch I ,mally held. in high speed gear ratio position, a solenoid operative to shift and hold the valve into circuit breaking position above such vehicle speed, and an auxiliary circuit for holding the switch in circuit making position under. certain engine operating conditions.

9. In control means for selecting gear ratios in a vehicle transmission powered by an engine having an intake manifold,devices operable to establish two gear ratios in the transmission,

control means for the devices comprising a fluid pressure system operative to selectively control said devices, a flow control valve in the fluid system, spring means normally maintaining the valve in position to cause engagement of the high speed gear ratio control device, a solenoid Operative when energized to shift said valve to cause engagement of the low speed gear ratio control device, an electric circuit connected with the solenoid including a master switch, two electromagnetic circuits for shifting said master switch, a governor controlled switch for selectively establishing the electromagnetic circuits, the electromagnetic circuit for moving the master switch to circuit closing position being energized below a predetermined vehicle speed, and the electromagnetic circuit for moving the master switch to circuit breaking position being energized above the predetermined speed, an auxiliary circuit connected with the solenoid circuit making electromagnet c system, a spring engaged switch in the auxiliary circuit, and a connection between the intake manifold and the switch in the auxiliary circuit 'whereby pressure in the manifold below a predetermined value will act on the switch to breakth'e auxiliary circuit and thereby release the master switch.

10. In a vehicle transmission of the planetary gear type having brake and clutch devices for selector switch to energize the electromagnetic establishing two gear ratios, control means for the devices comprising a iluid pressure system.

operative to selectively control said devices, a

how control valve in the system, spring means normally maintaining the valve in position to cause fluid pressure engagement oi the clutch device, a solenoid operative when energised to.

shii't'said valveand cause fluid pressure engagement oithe brake device, an electric circuit connected with the solenoicl including a make and break switch, electromagnetic means under conguano trol of a governor lor hol the switch in circult mg position below a predetermined vecombustion hicle speed and ice shifting the switch into circult breeizing posltlon above such vehicle speed, and an auxiliary circuit controlled by the will of. the vehicle crlriver. and connected with the;

solenoid.

ill. to a vehicle transmission ot the planetary gearing type having a broke device for establisha low speed gees ratio anal a clutch device for estoblismne s hieil speed gear ratio and powered by an internal comhustion engine having s we intake manifold, control m for the devices comprising a fluid pressure system operative to selectively control said; devices, a flow control valve in the fluid system, spring means normally maintaining the valve in position to cause fluid pressure engagement oi the clutch device, c.

- solenoid operative when energized to shift said valve and cause iiuid pressure, engagement of the brake device, an electric circuit connected s the electromagnetic means operative to move the master switch, into circuit making relation, a, diaphragm switch in the auxiliary circuit, spring means normally closing the diaphragm switch,

and a connection between the diaphragm-switch and the engine intake manifold whereby pressure at a value below maximum high pressure will move the diaphragm switch into circuit breaking position.

12. In as control system for selec ing ear ratiosswitch means controlling the operation of the electromagnetic means, and switch means controlled as a function of the torque demand on "the engine for establishing the second circuit with the solenoid, including a master switch for making and breaking the circuit, two electromagnetic means on opposite sides 0! the master switch for controlling its position, a switch common to the two electromagnetic means and shiitable to selectively energize the same, governor means driven by the vehicle and operative to control the electromagnetic means switch, said switch energizing the electromagnetic means iormoving the master switch into circuit making position below i on e, an auxiliary circuit tor around the speed sensitive switch means to overrule breaking oiihe pircuit by the said speed sensitive swltch.

Resonances crrm The following references are of record in the tile .0! this patent:

UNITED STATES PATENTS Number Name Date 1,813,731 Fleischel ..4 July 7, 1931 1,839,145 Foriohon Dec.29, 1931 1,893,644 Fleischel Jan. 10, 1933 2,210,239 Hale Aug. 6, 1940 2,251,625 Halo Aug. 5, 1941 2,260,406 Roche Oct. 28, 1941 2,380,491

1c. a l July 31, 1945 

